Hector's dolphin

Hector's dolphin is endemic to the coastal waters of New Zealand, where it is threatened by fisheries bycatch, pollutants and boat disturbance. Recent surveys estimate the total abundance at about 7,400 animals, fragmented into three populations around the South Island, and a sub-species (Maui's dolphin) on the west coast of the North Island.

Scientific Name

Habitat

Length

Weight

A rare and small cetacean, this dolphin is identified by a solidly built body with a gently sloping snout and a unique rounded (mickey mouse ear shaped) dorsal fin. Hector's dolphin takes its name from New Zealand zoologist Sir James Hector, who first collected the species in 1869.

Size

Adults measure between 1.2-1.4 m and weighs up to 50 kg.

Colour

The sides and back of this dolphin are light grey, with white "flames" reaching up along the sides of its body. The underside is whitish, while the face, flippers, the dorsal fin and tail are all black. There is a crescent-shaped black mark between eyes and blowhole.

A dolphin that plays with seaweed and blows bubbles

The species is found in inshore waters, including river mouths, estuaries and shallow bays, commonly within about 5 nautical miles of the shore. In winter the distribution reaches further offshore, out to 15 nautical miles.

Social Structure

This dolphin tends to occur in groups of up to five individuals, which may aggregate temporarily. Young are reported to play with seaweed, blow bubbles and are involved with other 'games' which are considered to be important social behaviours. Hector's dolphin emits sounds that are thought to be used for communication, notably the complex clicks produced in large groups.

Life Cycle

Females reach maturity at around 7 to 9 years of age, and males between 6 and 9 years.

Breeding

Courtship is a fairly elaborate process, involving chasing and belly displays. Usually, calves are born in late spring to early summer and the mother will not give birth again until the calf is fully independent.

Diet

Feeding is a group activity, and prey includes fish and squid.

Priority species

Whales and dolphins are a priority species. WWF treats priority species as one of the most ecologically, economically and/or culturally important species on our planet. And so we are working to ensure such species can live and thrive in their natural habitats.

Download

Four genetically distinct sub-populations

The species appears to have been historically much more abundant and widespread, including sub-populations off the east coast of New Zealand's North Island.

Current population and distribution

There are four genetically distinct populations of Hector's dolphin: off the west coast of North Island, and the west, east and south coasts of South Island. A current estimate puts the population at around 7,400 individuals.

This species was once hunted for bait, but this has now stopped. Due to the coastal habitat of Hector's dolphin, the species is vulnerable to a large number of different threats such as chemical pollution, vessel traffic and habitat modification.

Currently the main threat to the survival of this species is bycatch in net fisheries, particularly entanglements in gillnets that have been reported to occur throughout the species range.

Because Hector's dolphin exists in several discrete populations, this increases the risk of local extinctions from bycatch or a single pollution or disease episode.

There is a possibility that populations have declined to about a third to half of their size since 1970 because of gill net entanglement, with bycatch of this species occurring throughout its current range.

Habitat modification is another potential threat for the future. Although marine areas in New Zealand are relatively immune to degradation, coastal development such as the construction of ports and aquaculture are developing rapidly in some areas. Several deaths caused by ship strikes have been reported.

Recreational boat users interact with hector's dolphins throughout their range. Dolphin-watching tours are located at the center of the Banks Peninsula Marine Mammal Sanctuary, and new operations are beginning in the Lyttleton and Timaru areas of Canterbury. Possible impacts of recreational boating and tourism on Hector's dolphins are currently under study.

Action has been taken to protect the dolphin from fishing by closing part of the dolphin's range on the West Coast North Island to gillnetting, and by setting an allowable level of fishing-related mortality for part of the East Coast of the South Island.

WWF-New Zealand advocates increased protection of the dolphin through government fisheries and conservation decisions, and supports a community and schools awareness programme (currently for Maui's; a South Island programme is in development). It also carries out research to inform management, including a public sightings network for Maui's dolphin via a dedicated website and toll-free number; aerial surveys for distribution and abundance; genetic research; and brings together organisations which are working to protect Hector's dolphin.

WWF's objectives for Hector's dolphin and its subspecies Maui's dolphin are that by 2009, threats have been reduced to a level that allows the species to begin increasing in abundance, extending the range of Maui's dolphin and reducing isolation of Hector's dolphin populations.

The majority of WWF's work on the protection of Hector's and Maui's dolphins is carried out by WWF-New Zealand. Visit the WWF-New Zealand website for more extensive information on the species and WWF's efforts to bring them back from the brink of extinction.

How you can help

Support efforts to improve fishing gear by only buying seafood that is MSC certified. This can help to reduce the incidence of marine bycatch, which kills Hector's and Maui's dolphins and other marine life like turtles, whales, and seabirds.

Vote Earth by taking part in Earth Hour! As climate change is a growing threats for cetaceans (whales & dolphins) and other species, we need to send a message to our leaders that warming must be limited to under 2 degrees Celsius.

Spread the word! Click on the button to share this information with others via email or your favourite social networking service.

Stop their Extinction is a website dedicated to the survival of Hector's and Maui's dolphins. Use it to send a message to leaders, or adopt a dolphin or play the dolphin game.

Contents

Maui's dolphin

A small isolated group of Hector's dolphins remains on the west coast of New Zealand's North Island. These have recently been declared a subspecies called Maui's dolphin (Cephalorhynchus hectori maui), and in total number around 100 individuals. Hector's and Maui's dolphins are related to similar species in South Africa and South America.